U.S. patent application Ser. No. 913,569, discloses novel bonnets and contact lenses of high gas permeability comprising a class of polymers not used hitherto for contact lenses. These represent a significant advance in the state of the art, inasmuch as the transmission of oxygen through the contact lens to the cornea is sufficient to provide for the metabolic needs of the cornea. This solves the anoxia problem associated with many rigid contact lenses and among other things, permits longer wear times.
While very satisfactory, these contact lenses have a low surface wettability, the extent being dependent on the particular polymer composition, and this short-fall in surface wettability decreases the lens tolerance time by the lens wearer and may affect visual acuity.
Thus, one of the objectives of the present invention is to provide contact lenses in which the surface wettability of the contact lenses of high gas permeability described in the copending application is greatly improved. Another objective is to control the degree of wettability and thereby extend lens wearing time and comfort.